package com.clf.springBoot.listener;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import javax.servlet.annotation.WebListener;
import java.io.File;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;

@WebListener
public class LogFileListener implements ServletContextListener {

    public static Logger LOGGER = LoggerFactory.getLogger(LogFileListener.class);

    @Override
    public void contextInitialized(ServletContextEvent sce) {
        LOGGER.debug("======== 初始化 ServletContext 监听器 ========");

        // 获得目标文件夹，并判断其是否存在
        File destFolder = new File("/var/log");
        if (!destFolder.exists() || destFolder.isFile()) {
            return;
        }

        // 获取当前的时间字符串
        DateTimeFormatter dtf = DateTimeFormatter.ofPattern("yyyy-MM-dd");
        String currentDate = dtf.format(LocalDateTime.now());

        // 找出目标文件夹的子文件进行循环，如果包含当前时间字符串则保留，否则删除
        File[] files = destFolder.listFiles();
        for (File file : files) {
            if (!file.getName().contains(currentDate)) {
                file.delete();
            }
        }
    }
}